8 Graphical analysis of nickel tetracarbonyl

The following example illustrates features of the Graphical Analysis module, in analysing the ground state SCF wavefunction of Ni(CO)₄. Let us assume the following job has been used in constructing this wavefunction.

          #!/bin/csh -f
          setenv ed2 /scr1/user/nicomain
          setenv ed3 /scr1/user/nicodump
          setenv ed7 /scr1/user/ed7
          /scr1/wab/GAMESS-UK/bin/gamess << EOF
          title\ni(co)4 .. 3-21g / SCF total energy  -1947.868687
          zmat angstrom
          ni
          c 1 nic
          c 1 nic 2 109.471
          c 1 nic 2 109.471 3 120.0
          c 1 nic 2 109.471 4 120.0
          x 2 1.0 1 90.0 3 180.0
          o 2 co 6 90.0 1 180.0
          x 3 1.0 1 90.0 2 180.0
          o 3 co 8 90.0 1 180.0
          x 4 1.0 1 90.0 5 180.0
          o 4 co 10 90.0 1 180.0
          x 5 1.0 1 90.0 4 180.0
          o 5 co 12 90.0 1 180.0
          variables
          nic 1.831
          co 1.131
          end
          level 1.5
          enter
          EOF

Examination of the output reveals the following symmetry designation:

                                  ******************
                                  MOLECULAR SYMMETRY
                                  ******************
    
     MOLECULAR POINT GROUP    TD      
     ORDER OF PRINCIPAL AXIS   0
    
     SYMMETRY POINTS :
    
     POINT 1 :    0.0000000   0.0000000   0.0000000
     POINT 2 :    0.0000000   0.0000000   1.0000000
     POINT 3 :    0.0000000   1.0000000   0.0000000

and the following atomic coordinates:

           0.0000000      0.0000000      0.0000000       NI
          -1.9976836      1.9976836     -1.9976836       C
           1.9976836     -1.9976836     -1.9976836       C 
          -1.9976836     -1.9976836      1.9976836       C 
           1.9976836      1.9976836      1.9976836       C 
          -3.2316433      3.2316433     -3.2316433       O
           3.2316433     -3.2316433     -3.2316433       O
          -3.2316433     -3.2316433      3.2316433       O
           3.2316433      3.2316433      3.2316433       O

The following job may be used to construct a total density plot of the SCF wavefunction in a plane containing the Ni atom and two carbonyl groups, with the Ni at the centre of the plot: a contour plot will be generated on line printer output.

          #!/bin/csh -f
          setenv ed2 /scr1/user/nicomain
          setenv ed3 /scr1/user/nicodump
          setenv ed7 /scr1/user/ed7
          /scr1/wab/GAMESS-UK/bin/gamess << EOF
          restart
          title\ni(co)4 .. 3-21g / SCF total energy  -1947.868687
          zmat angstrom
          ni
          c 1 nic
          c 1 nic 2 109.471
          c 1 nic 2 109.471 3 120.0
          c 1 nic 2 109.471 4 120.0
          x 2 1.0 1 90.0 3 180.0
          o 2 co 6 90.0 1 180.0
          x 3 1.0 1 90.0 2 180.0
          o 3 co 8 90.0 1 180.0
          x 4 1.0 1 90.0 5 180.0
          o 4 co 10 90.0 1 180.0
          x 5 1.0 1 90.0 4 180.0
          o 5 co 12 90.0 1 180.0
          variables
          nic 1.831
          co 1.131
          end
          runtype analyse
          graphics
          gdef
          type 2d
          title
          square 2d grid ni(co)4 - total density
          calc
          type dens 
          title
          ni(co)4 - total density
          section 151
          plot
          type line 
          title
          ni(co)4 - total density
          vectors 1
          enter
          EOF